MIXTURE FOR PRECOAT OF POWDER SILVER-CONTAINING BIMETALLIC ELECTRIC CONTACTS Russian patent published in 1995 - IPC

FIELD: powder metallurgy. SUBSTANCE: copper powder is mixed with nickel acetate in the amount of 1-10 mas.%, and polyvinyl alcohol. The latter is taken in form of aqueous solution in the amount of 0.045-1 mas.%. Mixing is carried out for 10-15 min. Mixture is tubbed through sieve and dried at 100-120 C. Introduction of activator in form of nickel acetate promotes increased adhesion strength of working layer of bimetallic contact with precoat. Nickel acetate decomposes to form more active products with respect to sintering. Gaseous products of decomposition of polyvinyl alcohol possessing reduction properties positively affect the sintering process. EFFECT: improved technological properties. 3 tbl